BE1029901A1 - Expanded polystyrene with a latex for flooring applications - Google Patents

Abstract

The present invention relates to a kit suitable for the composite formation of a recyclable insulating floor layer, the kit comprising: a plurality of expanded polystyrene (EPS) granules with a density of 10-35 kg/m3 and a moisture absorption by immersion of up to 5%; and a binder, wherein the binder comprises a polymer-in-water emulsion. The invention further relates to a kit comprising recyclate, the kit suitable for forming a composite, recyclable insulating floor layer, the kit comprising: a plurality of recycled flakes comprising cut expanded polystyrene (EPS) granules bound by means of a first binder; and a second binder, wherein the binder comprises a polymer-in-water emulsion.

Description

1 BE2021/5864

EXPANDED POLYSTYRENE WITH A LATEX FRONT

FLOOR APPLICATIONS

TECHNICAL DOMAIN

The invention relates to insulating and lightweight floor elements. More specifically, the invention relates to a kit suitable for simply applying a thermal floor insulation, a method for applying a light floor insulation and said light floor insulation.

STATE OF TECHNOLOGY

Aerated concrete or aerated concrete is a type of concrete characterized by its low density and strong insulating capacity. By adding a gas-forming additive, a porous and insulating material is created. The air bubbles formed are not connected to each other. After the mass is taken out of the mold, it is cut into the desired product type: blocks, lintels, reinforced plates,

Expanded polystyrene (EPS) has been used for many purposes for over 50 years. It was originally intended as an insulation material and still has its largest application in this area, in addition to packaging. EPS products are manufactured in the form of blocks, plates or molded parts. The blocks can be cut into plates and many arbitrary molded parts. EPS building products are supplied pre-formed, such as EPS cavity walls and composite high-quality products such as sandwich panels or laminated roof insulation.

United States patent US 5,916,681 teaches the use of EPS as loose insulation, in a sandwich panel, as a preformed board and in combination with cement. US 4,1234,242 describes a loose insulation consisting of fibers and a granular material.

Concrete is heavy and has little thermal insulation, which is disadvantageous when insulating different floors. Furthermore, EPS is usually supplied either loose or preformed,

Compared to other insulation layers, this is an improvement within the insulation layers for floors; in particular in terms of:

2 BE2021/5864 - Recyclability: a major problem with current insulation material is the limited possibility of recycling or reuse; - Improved thermal insulation; - Improved compressive strength; - Reduced ecological impact; and - Simple method for installing such floor layers.

SUMMARY OF THE INVENTION

The invention relates to a kit suitable for the composite formation of an insulating floor layer according to claim 1. The inventors have surprisingly discovered that a moisture absorption by immersion of the EPS granules of a maximum of 5% is primordial for producing a thermally well insulating floor layer.

On the one hand, a low moisture absorption is necessary to allow recycling of a used floor layer into shredded flakes that can be used again with a similar floor layer, all the more so if washing the flakes is desired.

In addition, the exclusion of moisture absorption by the EPS granules is conducive to obtaining better thermal insulation. The thermal insulation can always be improved by providing a thicker insulation layer. Thicker insulation layers, however, dry and harden more difficult. For example, water from a polymer-in-water binder emulsion can remain in the insulation layer. This absorbed water considerably reduces the thermal insulation, which can partially negate the advantage of a thicker insulation layer. Furthermore, water can also enter the insulation layer via other routes, for example rising groundwater in the event of a faulty flood defence.

A preferred kit is described in claim 2. Such kits give rise to increased thermal insulation and compressive strength compared to kits with a lower weight percentage of EPS granules.

In a second aspect, the invention relates to a method for applying an insulating floor layer to a substrate, comprising (a) mixing a plurality of expanded polystyrene granules with a binder resulting in a substantially liquid insulating material according to a kit according to the first

3 BE2021/5864 aspect, (b) distributing the liquid insulation material on the substrate, and (c) curing the liquid insulation material into an insulating floor layer.

This is advantageous compared to building boards and other preformed building elements, since the kit can be used in any shape and with any dimensions. For example, the kit is also easy to transport and store in various forms, regardless of the shape of the designated insulating floor layer.

This method is advantageous over known insulating foams as it is simpler and cleaner. Due to a limited reaction, fewer harmful gases are released, less heat is generated as a result of exothermic reactions and the volume of the insulation material remains more or less constant. Furthermore, the steps in the second aspect can be carried out in the simplest order. For example, large amounts of granules and binder can be easily mixed in industrial concrete plants. Small amounts of binder can easily be applied to the EPS on the substrate. This way no further material is smeared. Finally, it is possible to simultaneously provide the EPS granules with binder and to apply the resulting slurry to the substrate.

This can be done, for example, with the aid of a blower or screw suitable for EPS granules, where they are provided with binding agent at the end. Finally, this is beneficial for leveling a floor, and properly insulating around pipes and other facilities in the floor of a building.

Another preferred kit is described in claim 3. Kits containing exclusively

EPS granules and binder, especially in this ratio, can be processed into a floor layer. This floor layer can later be cut into flakes; which flakes can be reprocessed into an insulating floor layer in combination with a binder. In a third aspect, the invention relates to a kit consisting of recycled flakes, suitable for a recyclable floor layer according to claims 12-15. The exclusion of further components prevents the undesired stacking or necessary processing of these further components. In particular, the addition of cement-based products is strongly discouraged, as they strongly crumble during the recycling process and thus greatly reduce the quality of the recyclate product.

In a fourth aspect, the invention relates to a method for recycling a floor layer.

In a further aspect, the invention relates to the insulating layer formed with a sealant according to the first aspect or by means of the method according to the second aspect,

This insulation layer has better thermal insulation and a lower specific weight than aerated concrete and concrete with EPS granules. Furthermore, this insulation layer has a better compressive strength than polyurethane foams. Furthermore, this insulation layer is recyclable, unlike cement and foam based products.

DETAILED DESCRIPTION

The invention relates to a kit suitable for forming a light, insulating floor layer. The invention furthermore relates to a method for providing an insulating floor layer. Finally, the invention relates to a light insulating floor layer.

Unless otherwise defined, all terms used in the description of the invention, including technical and scientific terms, have the meanings commonly understood by those skilled in the art of the invention. For a better appreciation of the description of the invention, the following terms are explicitly explained. "A", "the" and "the" in this document refer to both the singular and the plural unless the context clearly dictates otherwise. For example, "a segment" means one or more than one segment.

The terms “comprising”, “comprising”, “consisting of”, “consisting of”, “comprising”, “containing”, “containing”, “containing”, “containing”, “containing”, “containing” are synonyms and are inclusive or open terms indicating the presence of what follows, and which do not exclude or preclude the presence of other components, features, elements, members, steps, known or described in the art. “Dispersion polymerization” is a type of precipitation polymerization, meaning that the chosen solvent or solvent is both the reaction medium and a good

> BE2021/5864 is a solvent for the monomer and the initiator, but is not a good solvent for the polymer. As the polymerization reaction proceeds, particles of polymer form, forming a non-homogeneous solution. In dispersion polymerization, these particles are the site of polymerization.

Quoting numerical intervals by the endpoints includes all integers, fractions and/or real numbers between the endpoints, including these endpoints,

In a first aspect, the invention relates to a kit suitable for the composite formation of a recyclable insulating floor layer, the kit comprising:

A. a plurality of expanded polystyrene (EPS) granules with a density of 10-35 kg/m3 and a moisture absorption by immersion of up to 5%; and

B. a binder, wherein the binder comprises a polymer-in-water emulsion,

A problem with water-based emulsions is that water can be absorbed by EPS granules, EPS granules that absorb water show a significantly lower thermal insulation. This is especially a problem with thicker insulation layers, from which water escapes less easily. The inventors have discovered that coating the plurality of EPS granules allows EPS granules to be obtained with an immersion water absorption of less than 5%. The EPS granules with low water absorption therefore show an improved insulation value in the final product. The improvement also increases as the insulation layer increases in thickness,

Preferably, the plurality of expanded polystyrene (EPS) granules are fully pre-expanded. In a preferred embodiment, the EPS granules have a diameter between 1 and 8 mm. Granules smaller than 1 mm gave rise to too much dust. Granules larger than 6 mm had a negative effect on the insulating effect of the final product. Preferably, the diameter of the EPS granules is between 2 and 6 mm, even more preferably between 3 and 6 mm, most preferably between 4 and 6 mm. EPS granules with a diameter between 4 and 6 mm gave rise to the highest insulation value for the final material.

In a preferred embodiment, the EPS granules are "grey". Gray EPS is known to the skilled person, and consists of EPS granules containing graphite or carbon. These are produced by adding graphite or carbon when forming

6 BE2021/5864 unexpanded EPS beads. Gray EPS granules have better insulating properties. These are passed on to the final insulation material.

In a further preferred embodiment, the mass fraction of the EPS granules in the kit is between 0.40 and 0.80, preferably between 0.61 and 0.75, even more preferably between 0.62 and 0.75, even more preferably between 0.63 and 0.75, even more at preferably between 0.64 to 0.75, even more preferably between 0.65 to 0.75, even more preferably between 0.66 to 0.75, even more preferably between 0.67 to 0.74, even more preferably between 0.68 to 0.73.

In a preferred embodiment, the kit consists of the following components:

A. the expanded polystyrene (EPS) granules in a ratio of 61-75 wt.% to the weight of the complete kit; and

B, the binder in a ratio of 25-39 wt.% to the weight of the complete kit.

The inventors have discovered that the higher weight percentages of EPS granules lead to an improved insulation (lower lambda value) in both the initial product, but in particular in the recyclate that can be produced from this initial product. In this way a more favorable, higher-quality recyclate is obtained.

The binder is a polymer-in-water emulsion. The chain of this polymer mainly consists of carbon, oxygen, nitrogen, silicon such as polysiloxane. Preferably, the binder is a latex. Latex in this text is defined as a stable dispersion or emulsion of polymer particles in a solvent. This solvent is water. Even more preferably, the binder is a polymer-based binder. A binder based on dispersion polymerization will usually give rise to a latex, being a dispersion of polymer particles in a solvent. In a preferred embodiment, the polymer is selected from the group of: polystyrene (PS), polystyrene-butadiene copolymer, polybutadiene rubber (BR), isoprene rubber (IR), chloroprene rubber (CR), nitrile rubber (NBR), ethylene-propylene-diene monomer (EPDM), isobutylene isoprene rubber (IIR), polyisobutylene (PIB), silicone rubber (VMQ), fluorine rubber (FKM), ethyl vinyl acetate rubber (EVA), chlorosulfonated polyethylene rubber (CMS), acrylate rubber (ACM) or polyurethane rubber (AU or EU). More preferably, the polymer is selected from the group of: polystyrene (PS), polystyrene-butadiene copolymer, polybutadiene rubber (BR), isoprene rubber (IR), ethylene-propylene-diene

7 BE2021/5864 monomer (EPDM), isobutylene isoprene rubber (IIR), polyisobutylene (PIB) or ethyl vinyl acetate rubber (EVA). Even more preferably, the polymer is selected from the group of: polybutadiene rubber (BR), isoprene rubber (IR), ethylene-propylene-diene monomer (EPDM) and polystyrene-butadiene copolymer. Most preferably, the polymer is polystyrene-butadiene copolymer. Polystyrene-butadiene copolymer gives good adhesion to polystyrene surfaces. This is particularly important to prevent micro-cracks and associated thermal bridges. The inventors have surprisingly discovered that the use of a polystyrene-butadiene based binder allows lambda values to be obtained lower than 0.030 W/mK. Furthermore, polystyrene-butadiene copolymer has very good mechanical properties, resulting in a floor layer with high compressive strength. The use of a largely polystyrene based insulation layer for both beads and binder allows better recycling. The absence of heteroatoms, in particular chlorine and fluorine, but to a lesser extent also nitrogen, phosphorus and silicon contributes to this.

Even more preferably, the binder is based on dispersion polymerization or copolymerization, most preferably copolymerization. In a further preferred embodiment, the solvent used for dispersion polymerization or copolymerization may be water. This is environmentally friendly.

In a preferred embodiment, said binder, being a latex or based on dispersion polymerization or not, has a dry matter content between 20 and 70%, preferably between 25 and 65%, even more preferably between 25 and 60%, even more more preferably between 30 and 50%, even more preferably between 35 and 45%,

The use of a binder contained in a solvent allows the granules to be completely mixed in with the binder, whereby the surface of the EPS granules is completely covered thanks to the solvent. This improves the bond between the EPS granules and the polymer matrix. However, the solvent does not remain in large quantities in the end product, but leaves the insulation material almost completely during curing.

Preferably, the latex is formed by dispersion polymerization, which is stopped at a high degree of polymerization. In a further, preferred embodiment, a latex based on dispersion polymerization is capable of further polymerization after mixing with the EPS granules. This results in a strong,

8 BE2021/5864 three dimensional matrix created. Still, the polymerization during this last step can be very small; the vast majority of the polymer chains are formed in the production of the latex based on dispersion polymerization. In this way, the properties of both the polymer and the latex can be controlled without being dependent on the user. This is advantageous for use as a sealant, for example for do-it-yourselfers.

A latex can be supplied ready for use in liquid form. This is advantageous over known polymer foams, such as polyurethane, where exothermic reactions are necessary to form the polymer. The polymerization reactions also usually lead to a significant volume increase in foaming. This makes applying said materials to form a floor more difficult. Due to this on-site reaction, the microscopic and macroscopic properties of these insulation foams are less consistent.

The degree of polymerization, branching and end functionalities are easier to control,

This is because these properties only change very slightly, as most of the polymerization occurs during the production of the latex, and not when the latex is used as a binder. However, control over the degree of cross-linking is very important.

The curing of insulation foams is accompanied by volatile, possibly toxic and environmentally harmful gases. The curing of a water-based latex polymer is accompanied by the evaporation of water and little reaction. This is on the one hand more environmentally friendly and on the other hand healthier for the professional who installs the insulation.

In a further preferred embodiment, the latex has a Brookfield viscosity of 1 to 10000 mPa.s, preferably 5 to 5000 mPa.s, even more preferably 1 to 1000 mPa.s, even more preferably 50 to 500 mPa.s , preferably 50 to 300 mPa.s. This Brookfield viscosity is the viscosity measured with a

Brookfield viscometer with spindle 1, at 50 rpm at a temperature of 20°C.

These polymers insulate thermally better than cement. As a result, the sealant also has a better thermal insulation than aerated concrete based on similar EPS granules.

The preferred polymers provide a good balance of compressive strength, weight and insulation.

3 BE2021/5864

In a further preferred embodiment, the mass fraction of the binder in the kit is between 0.10 and 0.60, preferably between 0.20 and 0.50, even more preferably 0.22 to 0.45, even more preferably 0.25 to 0.40, even more preferably 0.25 to 0.39 , even more preferably 0.25 to 0.35, even more preferably 0.26 to 0.34, most preferably between 0.27 and 0.33. d10 is the particle size at which 10 wt.% of the expanded polystyrene granules have a smaller particle size and 90 wt.% of the expanded polystyrene granules have a larger particle size. d90 is the particle size at which 90 wt.% of the expanded polystyrene granules have a smaller particle size and 10 wt.% of the expanded polystyrene granules have a larger particle size. In a preferred embodiment, the EPS granules have a narrow particle size distribution. More preferably dso - dio, i.e. particle size distribution of the medium particle size 80 wt.% EPS granules, is less than 3.0 mm, more preferably less than 2.5 mm, more preferably less than 2.0 mm, more preferably less than 1.5 mm, more preferably less than 1.2 mm, more preferably less than 1.0 mm, more preferably less than 0.9 mm, more preferably less than 0.8 mm, more preferably less than 0.7 mm, more preferably less than 0.6 mm, more preferably less than 0.5 mm, more preferably less than 0.4 mm, more preferably less than 0.3 mm, more preferably less than 0.2 mm, most preferably less than 0.1 mm. Such narrow particle size distributions are advantageous on the one hand for laying the floor layer, in particular covering all granules with sufficient binder and leveling the resulting floor layer, for obtaining an insulating layer with constant and predictable insulation values and pressure values, and for optimal recycling of the floor layer into flakes. For example, with a narrow particle size distribution, the flake size can be better matched to the particle size of the EPS granules.

In a preferred embodiment, the kit comprises further additives. These can be added to the kit as an extra component, or they can be included in the latex or EPS granules. Additives that improve polymer properties are known to those skilled in the art, for instance flame retardants to improve the flammability of the final material, additives to improve chemical resistance and the like. The addition of materials with a high specific weight, such as sand or quartz sand, to increase the sound insulation of the material is also known.

10 BE2021/5864

In a further preferred embodiment, the kit contains lithium silicate as an additive. This additive is known as a densifier and hardener in concrete. Surprisingly enough, lithium silicate also appeared to have a very favorable effect on the compressive strength of a polymer matrix with EPS granules in between. In a further preferred embodiment, the mass fraction of lithium silicate is preferably between 0.005 and 0.15, even more preferably between 0.02 and 0.10, most preferably between 0.03 and 0.07.

In another preferred embodiment, the kit contains as few additives as possible, preferably no additives. In another preferred embodiment, the kit contains neither cement nor lithium silicate. In another preferred embodiment, the kit is free of foam formers, in particular free of polysorbate, sodium lauryl ether sulfate, sodium coceth sulfate, sodium dodecyl sulfate, sodium bicarbonate and isocyanate, in particular methylene diphenyl diisocyanate (MDI), hexamethylene diisocyanate (HDI) and isophorone diisocyanate ( IPDI). These additives, in particular cement, lithium silicate and foaming agents, cause problems during recycling. This makes the recycling process more difficult to control and/or significantly reduces the insulation quality of the recycled material.

In the most preferred embodiment, the kit comprises of the following components:

A. the expanded polystyrene (EPS) granules in a ratio of 61-75 wt.% to the weight of the complete kit; and

B, the binder in a ratio of 25-39 wt.% to the weight of the complete kit.

This gives rise to a building material with compressive strength higher than 150 kPa, lambda value of 0.030-0.036 W/mK. This material is cheaper to install than polyurethane foam (PUR) and has a higher compressive strength than PUR. The material is lighter than cellular concrete and has better thermal insulation.

In one embodiment, the kit further comprises reinforcement. This usually consists of metal, for example steel or a fibrous material. This reinforcement serves to improve the structural properties of the matrix. In a preferred embodiment, polymer-based fibers are used. These adhere better in a polymer matrix, and have a coefficient of expansion similar to the surrounding polymer matrix. This is beneficial to prevent delamination, the loosening of the

11 BE2021/5864 reinforcement from the polymer matrix formed by the drying of the latex.

In the second aspect, the invention relates to a method of applying an insulating floor layer to a substrate, comprising (a) applying a binding agent to at least part of a surface of a plurality of expanded polystyrene (EPS) granules to form a slurry, (b) applying the slurry to the substrate, and (c) curing the slurry to form an insulating floor layer.

In one embodiment, applying binder to the surface of the EPS granules includes mixing or mixing the granules well with the binder.

Mixing can be done in a variety of ways. Traditional concrete mixers or other methods of mechanical stirring or mixing are sufficient. Furthermore, the addition of liquid latex when applying the EPS granules to a floor, for example by means of a blower or feed screw, is also possible. Finally, the mixing can be done, especially for smaller quantities also by means of manual stirring.

The application of EPS and/or binder to the substructure includes any method of providing EPS granules and binder at the location where the structural element is formed.

A slurry in this text is a mixture consisting of small, solid particles and a liquid. In bulk, the properties of a slurry resemble those of a viscous liquid. In this text, the small, solid particles are always EPS granules. A slurry is easy to apply as it is "shape free". By this is meant that a slurry, just like a fluid such as a viscous liquid, will take on the shape of the container in which it is contained. This is advantageous for applying an insulation layer along, for example, pipes, foundations and structural elements. This is very beneficial for renovations to a home, such as insulating an existing home. Space is often limited within an existing frame, which has to be worked around.

Furthermore, the form-free character of the slurry ensures a tight connection. This is advantageous for the insulating effect, since small openings in the insulation give rise to thermal bridges. These thermal bridges are places where the insulation is interrupted, and have a very detrimental effect on the complete insulation of a home.

12 BE2021/5864

Finally, the slurry is not blown in under pressure. Known polymer foams are usually mixed simultaneously with their application, under pressure. Due to the high pressure, this work is usually not clean. For this purpose, the house is usually covered with paper or plastics, or it must be cleaned again. The slurry is preferably not applied under pressure.

The elements of the kit can be combined and applied simultaneously, separately and sequentially. The EPS granules and latex can first be combined to fill a slurry, for example in known concrete mixers, after which this slurry is applied to a floor. This makes it easy to mix large quantities of EPS with binder. It is also possible to apply the EPS granules and the latex to the floor and mix them in simultaneously. This way EPS and latex are mixed in evenly. Furthermore, material that comes into contact with the latex has been reduced. Finally, simultaneous mixing and application is the fastest method for many floors. It is also possible to apply the EPS granules first, and then add the latex. Conversely, the latex can also be applied first, which promotes careful application along existing elements, after which EPS granules are added. It is important that part of the latex is still more or less liquid before adding the EPS granules. It is also possible to work in layers, where one layer

EPS and latex are used for laying different layers of insulation material at different intervals. This can accelerate the curing of the insulation. A combination of the above is also possible. For example, it can be advantageous to first provide the irregular structural elements with a layer of latex, so that thermal bridges are further avoided.

Preferably, the steps (b) mixing the EPS granules and the binder and (c) applying the expanded polystyrene to a floor and (d) applying the binder to a floor can be carried out simultaneously, separately or sequentially.

“Levelling” or “levelling” is making the floor layer flat, even or level. The leveling of the slurry can be done in one or more steps.

This can be done both before and after the slurry has hardened into an insulation layer. Preferably, a first leveling takes place before the slurry hardens. This can be done very easily by spreading out the slurry, for example with a rake. If a completely flat surface is desired, the slurry can be completely smoothed out before or during curing. Furthermore, the surface can be polished or

13 BE2021/5864 sanded smooth. This is easier than with concrete since the material is considerably less hard.

In a preferred embodiment, the EPS granules and the binder are mixed in for 30 seconds to 15 minutes, preferably for 30 seconds to 10 minutes, even more preferably for 40 seconds to 5 minutes, even more preferably for 50 seconds to 4 minutes. ,

Curing of the slurry takes 2 to 96 hours. This mainly depends on the thickness of the insulation layer, and to a lesser extent on the temperature and humidity. The curing of the slurry can simply be done in the air. In a preferred embodiment, the hardening of the slurry is stimulated. This can be done by forced or natural convection above the floor surface, for example by properly ventilating the home. The use of absorbents can also speed up curing.

In a preferred embodiment, the thickness of the insulation layer is between 1 and 60 cm, preferably between 2 and 50 cm, even more preferably between 3 and 50 cm, even more preferably between 4 and 50 cm. The upper limit of 50 cm is generally only used when building a floor, and of course not an intermediate floor, where both an insulation layer and a structurally supporting and leveling layer are desirable. Above 60 cm, lower lambda values are noted,

In a preferred embodiment, the EPS granules and binder are applied under low pressure. When applying under high pressure, it is often difficult to work cleanly. Masking off and/or cleaning up leads to an extra cost.

The substructure is the surface on which the floor is applied. This can be a concrete layer, another floor layer, the subsoil, the foundation or a combination of the foregoing. Furthermore, the substructure can also comprise structural elements, conduits and the like. The slurry can easily be applied on top of these elements, regardless of their structure,

In a third aspect, the invention relates to a kit comprising recyclate, the kit suitable for forming a recyclable insulating floor layer, the kit comprising:

14 BE2021/5864

A. a plurality of recycled flakes comprising shredded expanded polystyrene (EPS) granules bound by a first binder; and

B. a second binder, wherein the binder comprises a polymer-in-water emulsion.

In a preferred embodiment, the average particle size of the recycled flakes dso,rec is at least 0.5 mm larger, preferably at least 1.0 mm larger, more preferably at least 1.5 mm larger, more preferably at least 2.0 mm larger, most preferably at least 2.5 mm larger, than the average particle size d50, ps of the bound expanded polystyrene (EPS) granules.

In a preferred embodiment, the first and second binder are based on the same polymer or copolymer. Even more preferably, the first and the second binder are based on the same polymer-in-water emulsion,

In a preferred embodiment, the plurality of recycled flakes have a density between 4 and 25 kg/m3, preferably between 15 and 25 kg/m3.

In one embodiment, an amount of (virgin) expanded polystyrene (EPS) granules can also be added to the recycled flakes. This addition will benefit the insulation value and compressive strength. Furthermore, a more manageable and predictable insulation layer is also obtained. However, the amount of recycled material is lower and the amount of fresh material is higher, which means that this measure also has an ecological impact. It is therefore advantageous to produce the first floor layer and all recycled floor layers in such a way that the amount of new (virgin) material remains as low as possible; in order to keep the fraction of recycled material as high as possible and to optimize the ecological impact of the first product and the recyclates based on it.

In a fourth aspect, the invention relates to a method for recycling a floor layer, this floor layer mainly consisting of bound expanded polystyrene granules, comprising the steps of: cutting said bound expanded polystyrene granules into recycled flakes,

In a preferred embodiment, the flakes are cut to an average particle size of the recycled flakes dso,rec of at least 0.5 mm

15 BE2021/5864 larger, preferably at least 1.0 mm larger, more preferably at least 1.5 mm larger, more preferably at least 2.0 mm larger, most preferably at least 2.5 mm larger than the mean particle size d50 of the bound expanded polystyrene (EPS) granules that are cut. This improves the compressive strength and insulation value of the recycled product.

In a preferred embodiment, the method further comprises the step of: binding the recycled flakes by means of a binding agent, preferably a polymer-in-water emulsion, even more preferably the same polymer binding said bound expanded polystyrene granules.

In a preferred embodiment, the recycled flakes have a density between 4 and 25 kg/m3, more preferably between 15 and 25 kg/m3.

The fifth aspect of the invention comprises an insulating floor layer formed with a sealant according to the first or third aspect, or by the method according to the second aspect.

This insulating floor layer is advantageous compared to aerated concrete thanks to a higher insulation value. Furthermore, the insulating floor layer is also lighter. Compared to conventional polymer foams, the insulating floor layer according to the present invention has a better compressive strength and is easier to install.

A floor layer according to this text can be located between the foundation and the ground floor, or between any two floors. The use of light insulation puts less stress on the structural elements of the building. A building according to this text can be any building, such as residences or office buildings, but also stables, warehouses and the like.

In a preferred embodiment, the final, solid insulating layer has a lambda value of less than 0.040 W/mK, preferably less than 0.037 W/mK, even more preferably less than 0.035 W/mK, even more preferably less than 0.034

W/mK, even more preferably lower than 0.033 W/mK, preferably lower than 0.032

W/mK.

The lambda value is the coefficient of thermal conductivity of a material and expresses how much heat is conducted per unit of time through a surface of 1m2 with a thickness of 1m at a temperature difference of 1°C (1K). This one is related to the

18 BE2021/5864 thermal resistance coefficient R of a material layer with thickness d if À = R/d. These units are defined according to ISO 10456.

A low lambda value is beneficial for good insulation. It has been found that the use of a polymer-based binder provides better thermal insulation than cement.

In a preferred embodiment, the structurally stable insulating layer has a minimum compressive strength of 100 kPa, preferably the minimum compressive strength is higher than 110 kPa, even more preferably the minimum compressive strength is higher than 120 kPa, even more preferably the minimum compressive strength is higher than 130 kPa, even more preferably the minimum compressive strength is higher than 140 kPa, even more preferably the minimum compressive strength is higher than 150 kPa.

This compressive strength is sufficient for use as a building material and a very good compromise between weight, insulation and structural element. The compressive strength is significantly higher than that of many polymer-based pre-printed sheets and foams.

In a preferred embodiment, the insulation layer has a specific weight of 10 to 50 kg/m3, preferably 15 to 35 kg/m3, even more preferably 15 to 30 kg/m3, even more preferably a specific weight of 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28 or 29 kg/m3.

A light, insulating material can be used advantageously in apartments and the like. This saves a lot of weight. Renovations often aim to add insulation without altering the structural elements of the home. Aerated concrete is often too heavy for this.

EXAMPLES

It is believed that the present invention is not limited to the embodiments described above and that some modifications or changes can be made to the examples described without revaluing the appended claims.

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Expanded polystyrene granules 1

Expanded polystyrene granules were purchased as non-expanded beads.

These non-expanded beads are "white", and therefore contain no graphite or carbon. These were expanded to a limited extent in a pre-foamer under the influence of steam. The pre-foamer is equipped with a mixer. Pre-foaming took place for 45s, with steam at a pressure of 0.25 bar. This steam has a temperature between 104 and 120°C.

After pre-foaming, the semi-expanded polystyrene granules are dried in a drying bed. In this drying bed, hot air is blown from under the semi-expanded granules. The hot air has a temperature of about 60° at the beginning of the bed. It drops to about 40°C at the end of the bed. The granules typically undergo two cycles through the drying bed. The EPS granules remain in the drying bed for approximately 2 minutes per cycle. The dry, semi-expanded PS granules are stored in a silo, where they also cool down further.

The semi-expanded polystyrene granules are fully expanded in a 4m x 1m x 1.2m block press. Superheated steam is used for this, at a pressure of 900 bar and a temperature of 210 °C, which acts on the pre-foamed polystyrene granules during a short peak of 6 seconds.

The moisture absorption upon immersion, after 24 hours, was 9%.

Expanded polystyrene granules 2

Example 1 was repeated with beads of the same commercial series but higher specific gravity. Furthermore, hydrophilic polymer was added to the steam tank of the block press at a ratio of 0.0001 wt.% to water.

The moisture absorption upon immersion of the produced EPS granules was now only 3%. This is probably due to the coating of EPS granules with the polymer during the expansion process and/or the closing of micropores in the EPS granules by the water-soluble polymer,

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Example 1: Kit

The EPS granules 1, with a diameter of 4 mm, were combined with a latex based on a dispersion copolymer. These were mixed well and poured into a mold to a height of 8 cm. Approximately 15-16 kg of pearls and 14 kg of latex were used for 1 m3 of final material. These are mixed together in a concrete mixer for 2 minutes. The slurry is then poured into a mold. The slurry hardens into a solid insulating layer after 4 hours. The lambda value of the solid insulating layer was measured as 0.0356 W/mK. The compressive strength was 40 kPa.

Example 2: Lithium silicate kit

In example 2 the example according to example 1 was repeated. When the latex and the EPS granules 1 were mixed in, a further 2 kg of lithium silicate hardener solution was added. A solid insulating layer was again produced from this.

2 kg of lithium silicate hardener was added. The solid insulation layer had a lambda value of 0.0364 W/mK. The compressive strength of the final material was 157 kPa.

Example 3: Kit with different EPS diameters

An insulating layer according to Example 2 was produced. Different diameters of EPS granules 1 were tested for their influence on the lambda value. The mass fraction of the EPS granules according to example 1-2 was preserved. Problems with dust were encountered for EPS granules with diameters below 1 mm. For EPS granules with diameters larger than 6 mm, the insulation value of the end result fell sharply. For EPS granules with a diameter between 1 and 6 mm, the lambda value was always between 0.0350 W/mK and 0.0370

W/mK. For EPS granules with a diameter between 4 and 6 mm, the lambda value was always between 0.0350 W/mK and 0.0362 W/mK.

Example 4: Kit with gray EPS granules

Example 1 was repeated, but the EPS granules are now “grey” polystyrene granules. These gray granules contain graphite and are known to those skilled in the art. From here

19 BE2021/5864 a solid insulation layer was again made. This insulation layer was also gray in color, giving rise to a lower lambda value of 0.0329 W/mK.

Example 5: Kit with gray EPS granules and lithium silicate

Example 2 was repeated, with the gray polystyrene granules from example 4. Here again it was found that lithium silicate greatly improves the compressive strength of the final material. The compressive strength was 159 kPa, and the lambda value for this product was 0.03344 W/mK. The acoustic insulation of the material was calculated at 17 dB/ 10 cm. The use of silicate significantly improved the compressive strength, but had a negative impact on the insulating properties.

Example 6: Floor

Concrete foundations were laid for a new building on a hard surface.

An EPDM foil was provided between the foundations and the substrate as a water barrier. A slurry was produced containing 16 kg of gray EPS beads, 13 kg of latex and 2 kg of lithium silicate per 1m3 of insulation material. These components were mixed in a concrete mixer for 4 minutes, forming a slurry. The slurry was poured on top of the EPDM foil up to the height of the foundations, with an average thickness of 8 cm. The minimum thickness was 5 cm. The slurry was leveled first with the serrated side of a harp, and then with the flat side of the rake. The slurry hardens into a solid, flat insulating layer.

Above was a layer of screed followed by floor tiles.

Example 7: Floor

During a renovation, the water pipes and cables for electricity and communication were exposed on a concrete base and partially renewed. A slurry with the same composition and by the same method as Example 5 was produced in a concrete mixer. The slurry was poured on top of the concrete layer. The slurry was pushed around the pipes and tubes with a rake. The resulting layer was 12 cm high and leveled. The pipes and tubes, except for their connections, were completely within the flat insulation layer.

20 BE2021/5864

Example 8: Mezzanine floor

An existing intermediate floor with wooden beams and OSB plates on top was further insulated and finished. A polypropylene foil was applied on top of the OSB plates. A slurry of the same composition and method as Example 5 was produced. This was mixed on top of the foil to a thickness of 4 cm. This was completely flattened. Wood laminate was applied above.

After this improvement, the floor was not only better thermally insulated, but also considerably quieter compared to walking or stepping on the intermediate floor. The applied insulation layer had a damping (acoustic) capacity.

Example 9:

Example 1 was repeated, with the EPS granules 2 with lower moisture absorption. The lambda value of the solid insulating layer was measured as 0.0321 W/mK. The compressive strength was 41 kPa.

Examples 10-12:

The insulating layer according to examples 1, 2 and 9 was cut into flakes with an average particle size of 7 mm. The flakes were rebound with a latex binder. The insulation values were 0.044 W/mK, 0.048 W/mK and 0.039 W/mK, respectively, for the recyclate from examples 1, 2 and 9.

Claims (15)

21 BE2021/5864 CONCLUSIONS 1, Kit suitable for the composite formation of a recyclable insulating floor layer the kit comprising: A. a plurality of expanded polystyrene (EPS) granules with a density of 10-35 kg/m3 and a moisture absorption by immersion of up to 5%; and B. a binder, wherein the binder comprises a polymer-in-water emulsion. A kit according to claim 1, the kit comprising: A. the expanded polystyrene (EPS) granules in a ratio of 61-75 wt.% to the weight of the complete kit; and B, the binder in a ratio of 25-39 wt.% to the weight of the complete kit. The kit according to claim 1 or 2, the kit containing: A. the expanded polystyrene (EPS) granules in a ratio of 61-75 wt.% to the weight of the complete kit; and B, the binder in a ratio of 25-39 wt.% to the weight of the complete kit. Kit according to any of the preceding claims 1-3, wherein the expanded polystyrene (EPS) granules have a density of 20-35 kg/m? and preferably have a density of 22-35 kg/m3. Kit according to any one of claims 1-4, wherein the expanded polystyrene (EPS) granules are coated. 6. Kit according to one of the preceding claims 1-5, wherein the binder has a viscosity of at most 300 mPa.s. Kit according to any of the preceding claims 1-6, wherein the binder comprises a polymer-in-water emulsion, wherein the polymer is a styrene-butadiene copolymer, Kit according to any of the preceding claims 1-7, wherein the kit has a chloride content of at most 0.1 wt.%, preferably 0.01 wt.%. 22 BE2021/5864 Kit according to any of the preceding claims 1-8, wherein the kit does not contain cement or lithium silicate. 10. Kit according to one of the preceding claims 1-9, wherein the kit is free of foam formers, in particular free of polysorbate, sodium lauryl ether sulfate, sodium coceth sulfate, sodium dodecyl sulfate, sodium bicarbonate and isocyanate, in particular methylenediphenyl diisocyanate (MDI), hexamethylene diisocyanate (HDI) and isophorone diisocyanate (IPDI). Kit according to any one of the preceding claims 1-10, wherein 10 wt.% of the expanded polystyrene (EPS) granules have a particle size smaller than d50 and 90 wt.% of the expanded polystyrene (EPS) granules have a particle size smaller than d50 , where dso — dio is less than 3.0 mm, preferably less than 1.5 mm, most preferably less than 0.5 mm. 12. Kit comprising recyclate, the kit suitable for forming a recyclable insulating floor layer, the kit comprising: C. a plurality of recycled flakes comprising shredded expanded polystyrene (EPS) granules bound by a first binder; and D. a second binder, the binder comprising a polymer-in-water emulsion, Kit according to claim 12, wherein the average particle size of the recycled flakes d50,rec is at least 1 mm larger, preferably at least 2mm larger, than the average particle size d50, ps of the bonded expanded polystyrene (EPS) granules. A kit according to any one of claims 12 or 13, wherein the first binder and the second binder comprise the same polymer. 15. Kit according to one of the preceding claims 12-14, wherein the plurality of recycled flakes have a density between 4 and 25 kg/m3, preferably between 15 and 25 kg/m3.